Regarding a non-reciprocal circuit element for use in a high frequency circuit, a structure including a metal cover is disclosed, in order to achieve miniaturization thereof, or achieve facilitation of implementation on a circuit board by reducing the number of components.
For example, PTL 1 discloses a structure in which a metal cover is placed on a wiring pattern formed on a circuit board in such a way as to make electrical contact with the wiring pattern through ferrite. Then, PTL 1 discloses a method of creating a metal cover by bending a metal plate, as a method of creating a metal cover.
In addition, in relation to the present invention, PTL 2 discloses a non-reciprocal circuit element in which a ground conductor provided on a rear surface of a dielectric body substrate is provided with a non-conductive body part on at least a part of a portion opposing an area covered with a metal cap on a surface of the dielectric body substrate.
In addition, in relation to the present invention, PTL 3 discloses a circulator in which a slab member is arranged with respect to a ferrite slab member in such a way that a magnet means saturates the slab member with a static magnetic field along a propagation direction of a signal passing through a coupler region.
In addition, in relation to the present invention, PTL 4 discloses a circulator including a dielectric body substrate, a ground conductor that covers a first surface of the dielectric body substrate, a magnetic body metal table, an inner conductor that is laid over a second surface of the dielectric body substrate, a spacer that is arranged on the inner conductor, and a magnet.